How Fast Did Dan Drive?
Date: 8/24/96 at 19:28:24 From: Anonymous Subject: How fast did Dan drive? I need an equation for this problem: It takes Kay 20 minutes to drive to work at 45 mph. Two minutes after she left home this morning, her husband Dan started out with her briefcase, which she had forgotten. If Dan gets to the office just as Kay does, how fast did he drive? Thanks, Dustin
Date: 8/25/96 at 15:15:32 From: Doctor Robert Subject: Re: How fast did Dan drive? Be careful not to mix minutes with miles per HOUR. Kay drives at 45 mph for 1/3 of an hour, so she drives 45 x 1/3 = 15 miles. Now Dan drives the same distance in 18 minutes (since he left two minutes after she did). Therefore, his speed must be distance divided by time: v = 15/(18/60hr) = 50 mph -Doctor Robert, The Math Forum Check out our web site! http://mathforum.org/dr.math/
Search the Dr. Math Library:
Ask Dr. MathTM
© 1994-2015 The Math Forum